Multiple antenna systems may be used in a number of different applications.
A system may, for example, be configured to operate the multiple antennas simultaneously.
A multiple antenna system may, for example, have multiple different antennas configured to operate at different frequencies or so that the system can operate in different frequency channels.
A multiple antenna system may, for example, have multiple different antennas configured to operate in orthogonal channels created by orthogonal signal encoding.
A multiple antenna system may, for example, have multiple different antennas configured to operate simultaneously in the same channel.
Diversity may be introduced between the multiple antennas by, for example, arranging the antennas so that they have diversity arising from different orientations and/or spatial separation.
The application of these various techniques may, for example, be used to create multiple input (MI), multiple output (MO) and multiple input multiple output (MIMO) systems.
A MO system may, for example may be used for beam-forming, spatial multiplexing or diversity transmission. A MI system may, for example be used for determining a bearing (reverse beam-forming), spatial multiplexing reception or diversity reception.
It would be desirable to improve multiple antenna systems.